Method for determining complexing capacity of medicine and copper ions

Abstract

The invention provides a method for determining the complexing capacity of a medicine and copper ions. The method comprises the following steps: uniformly mixing and stirring 100 [mu]l of the to-be-determined medicine and 100 [mu]l of a copper ion solution with the concentration of 0.1-10mmol / L; carrying out standing for 1-5 minutes; adding a mixture into 2ml of a rhodamine B hydrazine solution with the concentration of 0.1-5mmol / L; and carrying out a reaction for 3-10 minutes to obtain a to-be-determined solution. According to the technical scheme, the copper ions and the to-be-determined medicine are mixed in advance and then added into the rhodamine B hydrazide solution. If the to-be-determined medicine and the copper ions can be complexed, copper ion competition is formed between the to-be-determined medicine and rhodamine B hydrazides, so that the number of the open-loop rhodamine B hydrazides is reduced, finally the generated pink color becomes shallow, the ultraviolet absorptionand fluorescence emission intensities are reduced, and the changes of signals reflect the complexing capacity of the medicine and the copper ions.

Description

technical field [0001] The invention relates to a detection method, in particular to a method for measuring the complexing ability of medicines and copper ions. Background technique [0002] Although the soil has a certain self-purification ability for pollutants, when the harmful substances exceed the environmental capacity of the soil, the soil and its related ecosystems will be affected and destroyed. At present, heavy metal pollution in soil and its influencing factors have been widely studied at home and abroad. According to research, copper is an essential trace element for plants, high concentration will produce toxicity to plants, and its toxicity mainly depends on the activity of free copper ions rather than the total amount of copper elements. Since metal ions themselves have a certain amount of positive charge , easy to combine with soluble organic matter with negatively charged groups, the combination process of the two will change the adsorption balance between ...

AI Technical Summary

Problems solved by technology

For example, in the pH titration test, for ligands containing a large number of acidic groups, such as humic acid and fulvic acid, several hydrogen ions are replaced during the complex formation process, usually accompanied by a decrease in the pH value of the solution, and Often used as a qualitative indicator of complex formation, but this method is not intuitive and should only be used if the drug contains a large number of acidic groups

Another example, the AOAC method, the principle is to adjust the pH and alkalinity of the solution several times, so that the free metal ion hydroxide precipitates, and the precipitate is centrifuged, and the metal ion content in the clear liquid is the amount of complexed metal. This method It is necessary to separate free metal ions and determine the content of complexed metal ions. Generally, expensive and complicated instruments such as atomic absorption are required.

For another example, instrument analysis methods such as atomic absorption / emission spectrometry, inductive coupling method, electrochemical method (electrolytic analysis method), etc., the equipment used is more complicated, and when detecting copper, it is impossible to distinguish free and bound copper ions

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